Hi DOUBLE BOGEY,
only 135 experience in the sim, but real time on Bo105 (without SAS or ATT), BK 117 with SAS and ATT and EC155
The Bo 105 could be actually flown with weight shifting, if it was propperly trimmed out.
With SAS you will have the possibility to trim the bird - and if not disturbed, it will fly nicely straight and level - to give you the time to switch radios, punch in the GPS-waypoints and so on.
Evenso over water 3 or 4 AXIS AP is nicer to have, the workload won´t be excessive on a normal day.
Things will be different, if fog comes into the game or i.e. on the North See one of these grey days, where there is no horizon, the water having the same grey the sky has....